Ribbon shift mechanism for tabulating machines



May 19, '1936. R. DUNCAN ET AL RIBBON SBIFT MECHANISM FOR TABULATING MACHINES Original Filed Nov. 12, 1935 2 sheds-sheet 1 fiTTO/PNEY mm mm 5 mm mm May'19, 1936. R. DUNCAN T AL 2,041,637

' RIBBON SHIFT MECHANISM FQR TABULATING MACHINES Original Filed Nov. 12, 1935 2 She ets-Sheet 2 V inventor .IPOBE/PT oulvcfllv 4 E5 TE'I? Ft warn/v50 Gttomeg Patented May 19, 1936 UNITED STATES PATENT OFFICE mason smr'r MECHANISM roa manna-rum mcmmas Robert Duncan, Washington, D. 0., and later F. Wilkinson, Garrett Park, MIL, assignors to Government of the United States, represented by the Secretary of Commerce' Original application November 12, 1935, Serial 49,370. Divided and March 25, 1936, Serial No. 70,718

this application 4 Claims. (Cl- 197-181) (Granted under the m of March. a, 1883, as amended April so, 1928; 310 o. G. 751) such a mechanism for use in connection with tabulating machines, although it may be utilized in other associations.

The printing mechanism to which this mechanism is especiallyapplicable is shown and de-' scribed in copending application Serial Number 49,370, filed November 12, 1935, for improvements in Tabulating machines, out of which the mechanism about to be described is divided, and is therefore tobe considered as a division of said application.

The object of the invention is to provide a reliable, simple and durable mechanism for feeding the ribbon certainly in one direction as far as it should go, and then automatically reversing it, the reversal of movement being effected by building up of the ribbon upon one or the other of the spools to a point or to a degree at which the built up ribbon operates upon a shifting device to reverse the ribbon, the power for actuating the mechanism being derived from any suitable machine.

In the drawings illustrating the invention- Figure 1 is a front elevation of the shift mechanism mounted upon a support that is a part of the tabulating machine frame.

Figure 2 is a top plan view of Figure 1.

Figure 3 is a top plan view and edge view of the upper pivoted shift plate shown in Figure 2.

\ Figure 4 is a similar view of the bottom pivoted plate of Figure 2.

Figure 5 is a transverse section taken on the line 5-5, Figure 1.

Figure 6 is a side elevation of the mechanism for;i operating the shifting mechanism proper, an a Fig. '7 is a detail side viewand partial section of a cam and clutch; mechanism utilized to motivate the shift mechanism, looking in the direction of the arrows.

Referring to the drawings, and first to Figure 6, A designates apart of the base of a tabulatlng machine frame, and B a downwardly-extending flange, the like-of which is on the other side of the machine. Depending from the base is a hanger 0, another hanger like it being also attached to the base and properly spaced from the first, both hangers being utilized to support a. transverse normally non-rotating shaft I that may be extended to have additional hearings in the flanges B. Upon this shaft, fast to it, is an eccentric 2 surrounded by an eccentric strap 3 that has formed integrally therewith-an arm 4. A dog 5 is pivoted to the arm which has a shoulder 6 above its pivot and a tooth 1 below, the

be engaged by the catch ill on the lower end of a lever ll pivoted at it to a side plate of the frame, andhaving a button It at one end. A spring l3 seated in a recess in the base A tends to keep the catch lli normally in the path of movement of the shoulder portion of the dog for a purpose that will presently appear. East to.

the clutch disk is a sprocket l3 which constantly rotates so that rotary motion will be communicated to the shaft whenever the clutch disk and eccentric strap 3 are locked together, which occurs with each operation of the printing mechanism and when the ribbon mechanism is shifted.

The letter D designates a housing comprised in the main of two side plates D, one of which on the right-hand sideof the machine is shown, the plate having forwardly extending ears E, by which the housing is hung or pivoted to the shaft i, so it may be rocked toward and from the main frame, and latched thereto for the printing operation, and swung away to inspect the results of such operation, and for other purposes. The plates D 'of the housing are braced by cross pieces F and G, the upper brace F serving an important purpose in connection with the ribbon shift mechanism.

Journaled m the side plates 1) of the housing is a shaft it upon which is'mounted an eccentric l5, which rides in a slightly elongated slot IS in a rearward extension ll of a vertically operating arm l8, whose upper end is provided with a shoulder head IS, the shoulder being arranged to engage the teeth of a ratchet 20 on the platen or paper roll it. The lower end of the vertical arm is slotted as indicated at 22 for the passage of a headed stud 23, the slot and stud connection serving to keep the arm in place and to aid in guiding it in its vertical movement assisted by its engagement with the sides of a narrow slightly elongated recess 24 in the cross piece G-all clearly shown in Figure 6..

The shaft 14 carries a sprocket 25 fast thereto, andasimilar sprocket "is carried by the takes place.

normally non-rotating shaft I, the two being connected by a sprocket chain 21, shown in dotted lines only in Figure 6, the sprockets being alike so that the shafts l and I4 will be revolved at the same rate when a revolution of shaft 1 The-power for constantly driving. .the sprocket l3 by which the shaft I is driven may be from any suitable source.

Ribbon shift of the cross piece. .The shaft 36 carries a ratchet -wheel 36' engaged by a spring urged pawl 31' pivoted to the arm l8, there being a spring 31" for preventing backward movement of 4 the ratchet. Each sleeve 34 carries a toothed clutch member 38 arranged to be engaged by similar clutch'members 39 on the opposite ends of the long sleeve 40 which is slidably and rotatably mounted in hangers 4| secured to G. The shaft 36 extends through both of the sleeves 34 and also the sleeve 46, and while the short sleeves 34 are rotatable independently of the shaft '36,

ed on the cross piece G, there being also in the,

the sleeve 40 and said shaft must always rotate together, the means for assuring this joint motion being in the way of a pin 42 extending transversely through the shaft 36 with its ends protruding slightly through elongated slots 43 opposite disposed in the sleeve 40, as shown in Figure 1 and 5. Mounted centrally on the sleeve 46 and fast thereto is a disk 44 having an annulargroove 45 therein for the reception of a shift pin 46 extending from the under side of a vertical tab 41 integral with the under side of a rectangular shift plate 48. This plate is pivotally mounted on a rigid extension 49 extending forwardly from the cross piece G, and forms a' base for this plate '48, as well as another or upper plate 49' that rests upon the plate 48. The extension 49 carries a centrally located stud .56 near its front edge which is a pivot for the lower plate 48, and this pivot is extended considerably above said plate to serveadditional purposes, as will appear. The lower plate is provided at each upper edge with a tooth or spur 5| for engagement with shoulders 52 of a stop block 53 mountplate 48 two notches 54- arranged to receive a spring-back ball 55 protruding slightly from a socket in the block, the purpose of the ball and notches being to stabilize the plate 48 in either of its rocked positions. The plate 48 is further provided with an arcuate slot 56 for clearance of the pivot of the upper plate.

A-pin 51 on the plate 48 extends upwardly to be engaged by one or the other of the spurs 58 of the top plate 49' pivoted upon a stud 60 carried by the extension 49, and it is for the clearance of the stud that the slot 56 is provided in the plate 48, since the stud is stationary and the plate" must rock or shift at certain times.

7 The upper plate 48' has a curved slot 6| which permits the looking or shifting of plate 49' on its pivot, and the ends of the slot serve as stops to limit the throw of the plate 49' in either direction. This plate is further provided with a the link 63, which stud extends also through a stud 62 to which is pivoted a link 63, and attached to this link and to the stud 56 is a spring 64 that is gradually expanded as the ribbon builds up on a spool by a connection which will now be described, so as to be in readiness to snap 5 the top plate either to the right or left when the time comes to definitely operate the ribbon shift. The top plate 49' is provided with a stud 65 that passes through the arcuate slot 66 in Operation After each operation of the printing mechanism, which occurs after each run of cards, the

tabulating mechanism to which this ribbon shift is shown applied, it is desirable totake a print.

- At such time the button II (Figure 6) is pressed, 'rocking the lever ll, raising the catch l0, re- .2

leasing the dog 5, causing its leaf spring 5' to rock-the dog so that its tooth will enter a notch 8 in the clutch disk 9 locking the continuously rotating disk to the eccentric which is fast on the shaft I, thus bringing about a single revolu- 30 tion of said shaft, which brings the dog that has traveled with the shaft back to its normal position, or that'shown in Figure 6, when the catch III will again engage the shoulder of the dog and disengage its tooth from the notch, stopping 35 the rotation of all the parts. During this rotation of shaft I, the shaft I4 is rotated once, the cam l5 raising and lowering the arm l8, causing the pawl 31' to rotate the ratchet thedistance of one tooth, thus rotating the shaft 36 a short 40 longitudinally of the shaft 36 to give the rotation of the right-hand spool 29. The slowstepby-step rotation of the spool gradually winds the ribbon from the spool 28 on to 29. As the 50 ribbon builds up it works the shift bar 68 toward the left, the bar meanwhile through its loose central connection with the stud 65 of the top plate 48', slowly rocks said plate on its pivot 86 until the pin 62 passes the center, when the spring 64 will suddenly snap the plate the rest of the way, and in so doing a spur 58 will strike the pin 51 on plate 58, rocking said plate on its pivot 50, thus bringing a spur 5| against a shoulder 52 of the stop block to limit the movement 60 of the parts. Such a movement obviously shifts the other notch 54 to a position to be entered by the stabilizing ball 55. The shift is automatic. since the movement takes .place only at each printing operation in step-by-step order at far- 65 apart intervals.

We claim:

1. In a ribbon shift mechanism, in combination, a pair of ribbon spools, a ribbon on said spools, a rotatable shaft, a rotatable member for 70 each spool having constant operative engagement with the spools, a shiftable member on the shaft and rotating therewith and arranged to engage one spool rotating member at a time, a shift bar .between the spools and formed with ends in con- 75 tact with the ribbon on the spools, whereby as the ribbon is built up on one spool the shift bar will be gradually shifted, and means operated when the shift barhas passed a predetermined point to accelerate the movement thereof, and means operating at the time of such acceleration to shift the shiftable member to reverse a spool.

'2. The mechanism as claimed in claim 1 characterized in that the means operated by the shift bar comprises two plates capable of independent movement, one plate being provided with means engaged by the shift bar and also means for moving the other plate, such other plate having an extension engaging the shiftable member on the shaft, and a spring operating on the shift bar engaging plate to accelerate the movement of said plate when it is past center, to rock the other plate tsgactause it to shift the shiftable member on the 3. In a ribbon shift mechanism, in combination, a pair of ribbon spools, a ribbon thereon, a rotatable shaft, slidable clutch means carried by I the shaft for revolving the spools, a pair of independently pivoted plates, a shift bar in constant 25 engagement with the ribbon on the spools and arranged to be shifted by the built up ribbon thereon, operative connections between the shift bar and the plates, a spring operating upon one of the plates to accelerate its movement when said plate passes its pivotal center, means carried by one plate and arranged to engage means carried bythe other to operate said other plate, and connections between said other plate and the clutch means, whereby said means is shifted.

4. In a ribbon shift mechanism, in combina- I tion, a' pair of ribbon spools, a ribbon on said spools, a rotatable shaft. a rotatable member for each spool having constant operative engagement with each spool, a shiftable member on the shaft and rotating therewith, and arranged to engage one spool-rotating member at a time, a shift bar spanning the distance between the spools, a pair of pivoted links having their free ends pivotally connected with the ends of the shift bar, said links being provided with members in constant engagement with the ribbon on the spools, whereby as the ribbon is built up upon one spool the bar will be gradually shifted, and means operated when the shift bar has passed a predetermined point to accelerate the movement thereof, and means operating at the time of suchaecelew tionto shift the shift bar to reverse a spool.

ROBERT DUNCAN. LESTER F. WILKINSON. 

